The geological legacy of Hurricane Irene: Implications for the fidelity of the paleo-storm record

Dept. of Geography and Earth Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina 28223 USA

ABSTRACT

Paleotempestology has become more contentious in recent years because the exact nature of storm deposition and preservation is still poorly understood. Whereas historical records of hurricanes along the Atlantic coast are limited to the past 300 years, and reliable instrumental records extend back only half that length of time, proxy records taken from coastal sedimentary archives offer the potential to extend this record several thousand years, offering better statistical constraints on hurricane prediction. Two primary proxies have been the most studied during the last decade: sedimentary criteria and microfossils. In this study, we used a microfossil-based proxy—displaced marine foraminifers—to investigate a 1500-year paleostorm record of Onslow Bay, North Carolina, USA, and to compare marsh sediments and foraminifers pre- and post–Hurricane Irene, which made landfall in Onslow Bay on 27 August 2011. We found fewer hurricanes archived in the 1500 years of back-barrier marsh strata than have made landfall in Onslow Bay since 1950. This absence of preserved hurricane deposits, as well as the lack of a definitive signature from Hurricane Irene, suggests that caution should be used with respect to the sensitivity of sedimentological or micropaleontological proxies in paleotempestology studies. We conclude that, at best, only direct strikes from intense storms are being preserved, and it is likely Hurricane Irene’s landfall will not be detectable in the future in the marginal-marine sediments from this region.